scispace - formally typeset
Search or ask a question
Topic

Hydrostatic equilibrium

About: Hydrostatic equilibrium is a research topic. Over the lifetime, 2451 publications have been published within this topic receiving 62172 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: In this article, a model for the self-similar collapse of magnetized isothermal cylinders was developed, and it was shown that a low magnetization results in density profiles that behave as rho ~ r^{-4} at large radii.
Abstract: We develop models for the self-similar collapse of magnetized isothermal cylinders. We find solutions for the case of a fluid with a constant toroidal flux-to-mass ratio (Gamma_phi=constant) and the case of a fluid with a constant gas to magnetic pressure ratio (beta=constant). In both cases, we find that a low magnetization results in density profiles that behave as rho ~ r^{-4} at large radii, and at high magnetization we find density profiles that behave as rho ~ r^{-2}. This density behaviour is the same as for hydrostatic filamentary structures, suggesting that density measurements alone cannot distinguish between hydrostatic and collapsing filaments--velocity measurements are required. Our solutions show that the self-similar radial velocity behaves as v_r ~ r during the collapse phase, and that unlike collapsing self-similar spheres, there is no subsequent accretion (i.e. expansion-wave) phase. We also examine the fragmentation properties of these cylinders, and find that in both cases, the presence of a toroidal field acts to strengthen the cylinder against fragmentation. Finally, the collapse time scales in our models are shorter than the fragmentation time scales. Thus, we anticipate that highly collapsed filaments can form before they are broken into pieces by gravitational fragmentation.

41 citations

Journal ArticleDOI
TL;DR: In this article, the pull-in instability and free vibration of circular microplates subjected to combined hydrostatic and electrostatic forces are investigated, and a generalized differential quadrature (GDQ) method is employed to discritize the governing differential equations along with simply supported and clamped edge supports.
Abstract: In the present study, the dynamic pull-in instability and free vibration of circular microplates subjected to combined hydrostatic and electrostatic forces are investigated. To take size effects into account, the strain gradient elasticity theory is incorporated into the Kirchhoff plate theory to develop a nonclassical plate model including three internal material length scale parameters. By using Hamilton’s principle, the higher-order governing equation and the corresponding boundary conditions are obtained. Afterward, a generalized differential quadrature (GDQ) method is employed to discritize the governing differential equations along with simply supported and clamped edge supports. To evaluate the pull-in voltage and vibration frequencies of actuated microplates, the hydrostatic-electrostatic actuation is assumed to be calculated by neglecting the fringing field effects and utilizing the parallel plate approximation. Also, a comparison between the pull-in voltages predicted by the strain gradient theory and the degenerated ones is presented. It is revealed that increasing the dimensionless internal length scale parameter or decreasing the applied hydrostatic pressures leads to higher values of the pull-in voltage. Moreover, it is found that the value of pull-in hydrostatic pressure decreases corresponding to higher dimensionless internal length scale parameters and applied voltages.

41 citations

Journal ArticleDOI
TL;DR: In this paper, a yield condition which takes into account the influence of hydrostatic stresses is discussed, and an application to the determination of the burst pressure of a perfectly plastic spherical shell is given.
Abstract: The paper discusses a yield condition which takes into consideration the influence of hydrostatic stresses. It is shown that many experimental observations made in plasticity can be described satisfactorily by such a yield condition. An application to the determination of the burst pressure of a perfectly plastic spherical shell is given.

40 citations

Journal ArticleDOI
TL;DR: In this paper, the authors analyzed more than 300 simulated massive clusters from the Three Hundred Project, and investigated the connection between mass bias and several diagnostics extracted from synthetic X-ray images of these simulated clusters.
Abstract: Accurate and precise measurement of the masses of galaxy clusters is key to deriving robust constraints on cosmological parameters. However, increasing evidence from observations confirms that X-ray masses obtained under the assumption of hydrostatic equilibrium might be underestimated, as previously predicted by cosmological simulations. We analyze more than 300 simulated massive clusters from the Three Hundred Project, and investigate the connection between mass bias and several diagnostics extracted from synthetic X-ray images of these simulated clusters. We find that the azimuthal scatter measured in 12 sectors of the X-ray flux maps is a statistically significant indication of the presence of an intrinsic (i.e., 3D) clumpy gas distribution. We verify that a robust correction to the hydrostatic mass bias can be inferred when estimates of the gas inhomogeneity from X-ray maps (such as the azimuthal scatter or the gas ellipticity) are combined with the asymptotic external slope of the gas density or pressure profiles, which can be respectively derived from X-ray and millimeter (Sunyaev-Zeldovich effect) observations. We also obtain that mass measurements based on either gas density and temperature or gas density and pressure result in similar distributions of the mass bias. In both cases, we provide corrections that help reduce both the dispersion and skewness of the mass bias distribution. These are effective even when irregular clusters are included leading to interesting implications for the modeling and correction of hydrostatic mass bias in cosmological analyses of current and future X-ray and SZ cluster surveys.

40 citations


Network Information
Related Topics (5)
Magnetic field
167.5K papers, 2.3M citations
81% related
Turbulence
112.1K papers, 2.7M citations
80% related
Boundary layer
64.9K papers, 1.4M citations
76% related
Boundary value problem
145.3K papers, 2.7M citations
75% related
Particle
96.5K papers, 1.9M citations
75% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023282
2022708
202167
202089
201998
201893